However, at the same time, Mike Pompeo, the Secretary of State, said he was hopeful Washington could still strike a new nuclear deal with Europe.

The diverging tones suggest splits within the administration about how to work with the international community in reining in Iran’s military and territorial ambitions.

For its part, Iran at the weekend launched a diplomatic effort to keep the deal alive.

President Hassan Rouhani said: “If the remaining five countries continue to abide by the agreement, Iran will remain in the deal despite the will of America.”

Theresa May spoke with Mr Rouhani on Sunday afternoon to reiterate the UK's position of upholding the nuclear deal, Downing Street confirmed on Sunday night.

“She said it is in both the UK and Iran’s national security interests to maintain the deal and welcomed President Rouhani’s public commitment to abide by its terms, adding that it is essential that Iran continues to meet its obligations," a No 10 spokesperson said.

But speaking on Fox News Sunday, Mr Pompeo offered more conciliatory language and insisted the decision to withdraw had not been aimed at the UK or the European Union.

“I'm hopeful in the days and weeks ahead we can come up with a deal that really works, that really protects the world from Iranian bad behaviour, not just their nuclear programme, but their missiles and their malign behaviour as well," he said.

In announcing his decision to withdraw, Mr Trump was making good on a campaign promise. He and American officials have long expressed concern that the nuclear deal did nothing to stem Iranian missile tests or thwart its activities supporting militias or proxies throughout the Middle East.

Javad Zarif in Beijing as he attempts to shore up what is left of the nuclear dealCredit:
Reuters

For its part, Tehran has launched a diplomatic effort to keep the deal together. Javad Zarif, the foreign minister, has embarked on a tour of signatories aimed at persuading them to help protect Iran from US sanctions.

After meeting his counterpart in Beijing, Mr Zarif said on Sunday: “We hope that with this visit to China and other countries we will be able to construct a clear future design for the comprehensive agreement.”